Spring ejector for metal punch



Oct. 8, 1963 w. F. REECE 3,106,120

SPRING EJECTOR FOR METAL PUNCH Filed April 15, 1960 INVENTOR. Vl/I/ if We e ce United States Patent O 3,166,126 j SPRING EJECTR FR METAL PUNCH William F. Reece, Detroit, Mich., assignor to Allied Products Corporation, Detroit, Mich., a corporation of Michigan Filed Apr. l5, 1960, Ser. No. 22,558 2 Claims. (Cl. S3-l28)V vThe present invention broadly pertains to punching dies and more particularly to an improved ejector for removing the cutout slug or core from the cutting face of-a punching die.

In punching dies of the general type herein described various means have been employed to eject the cutout. slug or core 'from the cutting tace of the punching die at the completion of each punching stroke. Ejection means of the plunger type -axially disposed in the punching die are conventionally comprised of a plurality of parts which are specilically designed for a particular punching die and are ot limited interchangeability. In addition, the punching dies incorporating such ejector plungers are conventionally comprised of a plurality of assemblable and disassemblable 'sections which must be accurately machined to accommodate the ejector means and require the punching die to be assembled and disassembled each time the ejector means are replaced or the punching die sharpen-ed. Because of these factorsejector-type punching dies heretofore known have been costly to manufacture and are tedious and time consuming to repair.

lt is the principal object of the present invention-to provide a unique unitary resiliently biased ejector that is simply accommodated in a unitary punching die enabling quick `and simple installation and removal thereof.

Another object of this invention is to provide `an ejector that is readily moditied for use in punching dies of varying lengths thereby substantially increasing the inter-v changeability thereof.

Still another object of this invention is to provide a punching die incorporating therein a unique ejector that is of simple design, durable operation, land inexpensive to manufacture.

The `foregoing and other objects of this invention are achieved by an ejector characterized by a helical coil fspring disposed in an axial bore'in the punching die and having a straight ywire shank 'portion integrally connected thereto extending axially through a small bore through the tip ot the die and projecting beyond the cutting face surface thereof so as to contact and resiliently eject a cutout core or blank from the cutting tace of the die at the completion of each punching stroke.

Other objects and advantages of the-present invention will become apparent from the following detailed descrip- 3,106,123 Patented Oct. 8, 1963 Ice may be simplyreleased from the punch holder 10 by inserting a suitable release pin (not shown) upwardly through an aperture 26 in the block member 16 :adjacent to the central bore `8 `and in communication with the angular bore 18 whereby the ball 22 is pushed upwardly in opposition to the coil spring 20 and out of engagement with the groove 24 enabling the withdrawal of the shank portion ejfrom the central bore 8. When the punching die 2 is installed in the punch holder 10 as shown in the dnawing, end sur-face .28 of the shank portion 6 is in firm abutting relationship with the base pad 14.

The punching die 2 is shown in the drawing in the lowered position wherein the end of the cutting tip por- The die holder 34 is detachably and adjustably securedV to a bolster orvbed A42 of the press. As shown in the drawing the lower die 32 is provided with a counter bore 44 in axial alignment with the bore 3h and in communicationl with a bore 46 through the bed 42 providing therewith an ejection chute for discharging the slugs or cores 48 punched out of the sheet material Sti.

At the completion of the downward Istroke of the punching die as shown in the drawing, the core `48 is removed from the cutting face 5 of the punching die by a unique ejector `51 comprising the present invention. The ejector 51 is comprised of a coiled wire or spring portion 52 and Y a straight wire tang 54 extending from the center of and tion taken in conjunction with the accompanying drawing which is a vertical -fragmen tary sectional view of a typical punch and die set installed in a suitable press and illustrating in partic-ular'a novel ejector incorporating the preferred embodiments of this invention.

As shown in the drawing a cylindrical punching Vdie 2 comprising a cutting tip portion 4 having a cutting face 5 at the end thereof and a cylindrical shank portion 6 is removably disposed in a central bore tl of a punch re-l tainer or holder iii' which is detachably secured to a movable slide or ra-m l2 of a punch press. The punch holder lll is comprised of a base padV lli lixedly secured to a l block member l5 having an angularly disposed bore 1S therein communicating with the central bore 8. Y Resiliently biased engaging means comprising a coil spring contact with a teardrop shaped groove 2li in the periphery of the shank portion 6 preventing inadvertent withdrawal in axial alignment with the coiled wire portion 52. The straight tang S4 is slidably disposed and reciprocable in a bore oextending axially through the cutting tip portion 4 ofthe punching die 2 and projects beyond and substantially perpendicular to the cutting face 5. The tang 54 should be closely "fitted in the bore 56 so as to provide suiiicient clearance therebetween to enable guided sliding ,movement and prevent lateral deflection of the tang under load which might tend to cause binding. The coiled wire portion/52. is comprised of, closedvor nested coil sections 53 and tan open coil section `60 which provides axial resiliency and enables axial movement of the straight tang v5d integrally connected to and axially extending from the lower portion thereof. The nested coil sections 5S and the open coil section 60 are guidably and slidably disposed in a central bore d2 extending through the punching die 2 and disposed in axial alignment and in communication with the bore 56 through the cutting tip portion 4 of the .punching die.

The upper end of the ejector 51 is seated against the base pad i4 of the punch holder 1li and is of a plain end or can be squared by :closing and/or grinding tor better seating characteristics. 'Iihe lower end of the coiled wire portion 52 of the ejector 5l is seated on an annular shoulder 64 at the base of the central bore 62 which limits the downward axial sliding movement of the tang 54.

The free length of the coiled wire portion 52 of the ejector can be simply controlled by varying the length or" the open coil section 6) rand preferably by cutting off a portion of the upper end of the closed coil section 59 which enables an ejector of a given coil diameter to be adapted to punching dies having Shanks of various lengths. For lany `given punching die it is preferred that the free length' of the coiled wire portion 52 of the ejector 51 exceeds the length of the central bore 62. whereby the open coil section 6l) will be in compression when installed .in the punching die. The length of the tang 54 of the ejector 5l maybe cut to any desired length depending on the length of the cutting tip portion y4- o-f a particular punching die so when in the fully projected position as limited by annular shoulder `64 a small portion thereof will project beyond the cutting rface 5 of the punching die. It will of course be appreciated by those skilled in the art that the open coil section i6@ is designed to provide suiicient axial deflection between the open position and a nested compressed position to enable the projecting end portion of the tang 54 to completely retract within the cutting tip portion 4. 1t is also preferred that the open coil section 6@ be disposed intermediate the ends of the coiled wire portion 52 of the ejector providing a short nested coil section S8 at the lower end thereof from which the tang 54 axially extends. The short nested coil section 58 adjacent to the tang 54 is substantially rigid and serves as a sliding guide bearing assuring continuous accurate .align-ment of the upper portion of the tang with the bore 56 thereby minimizing binding between the-tang and bore S6 during the sliding movement of the tang.

When the punching die 2 is withdrawn from the punch holder i@ the ejector 51 can be simply and quickly removed by sliding it out. Accordingly, the punching die 2 may be sharpened or the ejector replaced without the necessity, as has .been heretofore practiced, of first disassembling the punching die to remove the ejector means. After .the cutting face of the punching die has been ground the end of the tang 54 lmay be recut or ground to the desired length.

In operation, lwhen the punching die comes in contact with the sheet material 5d during lthe downward punching stroke of the slide 12 as viewed in the drawing, the end of the tang 54 is forced upwardly through the bore 56 until it is flush with the cutting face 5 thereby partially compressing the open coil section `60. Alfter the cutting tip portion 4 of the punching die has perforated the sheet material 50, the upward force :against the tip of the tang 54 is released whereby the open coil section '69 axially biases the tang 54 downwardly separating the slug 4-8 `from the cutting face 5 of the punching die -as shown in the drawing.

It will of coursetbe appreciated by those skilled in the art that the ejector hereinabove described in relation to the specific perforatingV punch shown in the drawing is equally applicable to other types of punching dies, blanking dies and the like wherein one or more ejectors may be incorporated yfor separating the cutout slug or core from the cutting face of the punch. Accordingly, while the preferred embodiment herein described is Well calculated to yfulfil the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope of fair meaning of the subjoined claims, i

4. What is claimed is:

In a punching die including a body member having a cutting face thereon, -a portion of the body member defining a first bore extending inwardly a distance from the surface opposite to the cutting face and a second bore extending inwardly from the cutting lface and disposed in axial end communication with the first bore, the improvement comprising an ejector' Adisposed inthe vfirst and second boresV for ejecting a `cutout slug from the cutting face of the die, said ejector comprising a helical coil spring portion removably disposed in the first bore and a straight tang extending axially yfrom and integrally affixed to one end of sai-d coil spring portion, `said tang slidably disposed in the second bore and resiliently reciprocable therein to and from a projected position wherein the end of said tang projects a distance beyond the cutting face and a retracted position vwithin the die.

2. In a .punching die including a body member having i a cutting face thereon, a portion of the body member definitiU a first bore extending inwardly a distance from the surface opposite to the cutting face and a second bore extending inwardly frorn the cutting face and disposed -in axial end communication 4with the rst bore, the improvement comprising 4an ejector disposed in the first and second bores for ejecting a cutout slug from the cutting face of the die, said ejector comprising a helical coil spring portion removably disposed in the first bore and a straight wire tang extending axially from and integrally aixed to one end of said coil spring portion and slidably disposed in the second bore, said coil spring portion cornprising at least one nested coil section disposed at each of the ends thereof and at least one open coil section disposed intermediate tfhc end of said nested coil sections, said open coil section providing for axial resilient reciprocation of said tang in the second bore to and `frorna projected position Kwherein a portion of said tang projects a distance beyond the cutting `face and a retracted position wherein said tang is retracted within the die.

References Cited in the file of this patent UNITED STATES PATENTS 115,157 Brown May 23, 1871 931,282 Dillingham Aug. 17, 1909 2,316,650 Klopfenstein Apr. 13, 1943 2,350,436 Whistler I une 6, 1944 2,616,684 Y Richter Nov. 4, 1952 2,713,905 Hartley July 26, 1955 2,747,859 Rager May 29,1956 2,917,960 Gargrove Dec. 22, 1959 

2. IN A PUNCHING DIE INCLUDING A BODY MEMBER HAVING A CUTTING FACE THEREON, A PORTION OF THE BODY MEMBER DEFINING A FIRST BORE EXTENDING INWARDLY A DISTANCE FROM THE SURFACE OPPOSITE TO THE CUTTING FACE AND A SECOND BORE EXTENDING INWARDLY FROM THE CUTTING FACE AND DISPOSED IN AXIAL END COMMUNICATION WITH THE FIRST BORE, THE IMPROVEMENT COMPRISING AN EJECTOR DISPOSED IN THE FIRST AND SECOND BORES FOR EJECTING A CUTOUT SLUG FROM THE CUTTING FACE OF THE DIE, SAID EJECTOR COMPRISING A HELICAL COIL SPRING PORTION REMOVABLY DISPOSED IN THE FIRST BORE AND A STRAIGHT WIRE TANG EXTENDING AXIALLY FROM AND INTEGRALLY AFFIXED TO ONE END OF SAID COIL SPRING PORTION AND SLIDABLY DISPOSED IN THE SECOND BORE, SAID COIL SPRING PORTION COMPRISING AT LEAST ON NESTED COIL SECTION DISPOSED AT EACH OF THE ENDS THEREOF AND AT LEAST ONE OPEN COIL SECTION DISPOSED INTERMEDIATE THE END OF SAID NESTED COIL SECTIONS, SAID OPEN COIL SECTION PROVIDING FOR AXIAL RESILIENT RECIPROCATION OF SAID TANG IN THE SECOND BORE TO AND FROM A PROJECTED POSITION WHEREIN A PORTION OF SAID TANG PROJECTS A DISTANCE BEYOND THE CUTTING FACE AND A RETRACTED POSITION WHEREIN SAID TANG IS RETRACTED WITHIN THE DIE. 